TONY JONES, PRESENTER: After more than three years, the investigation into allegations against officials of the Health Services Union, including the embattled Labor MP Craig Thomson, is tonight stuck in a legal gridlock.

The Opposition is furious after the Director of Public Prosecutions said it had no power to investigate and no brief of evidence to work with. That's after Fair Work Australia provided them with a detailed report into financial and administrative irregularities in Mr Thomson's old union.

But today the Commonwealth Prosecutors Office crushed those hopes, saying the 1,100-page Fair Work Australia report handed to it yesterday didn't amount to evidence of criminal activity.

"The CDPP is not an investigation agency," a statement today said. "It does not have investigative powers and is not able to conduct a criminal investigation."

TONY ABBOTT, OPPOSITION LEADER: Something wrong has happened here. A thousand days of investigation now appear to have hit a brick wall.

TOM IGGULDEN: And the Opposition Leader says if what's been presented so far to the DPP doesn't count as evidence, Fair Work Australia needs to try again.

TONY ABBOTT: Fair Work Australia needs to ensure that its investigation is converted into a brief of evidence so that the DPP can ensure that justice is done, that the guilty parties are identified and prosecuted.

TOM IGGULDEN: But legal advice from the Australian Government solicitor to Fair Work Australia advises against handing its investigation to police who could start a criminal investigation, saying privacy legislation "does not authorise the disclosure of the information in question to the NSW and Victorian police forces".

The Government solicitor's advice was sought on the same day an eminent non-government lawyer told Fair Work "There is nothing in the Registered Organisations Act that would prevent a good faith disclosure of information to a State law enforcement agency".

The Opposition Leader says the investigation's being deliberately stalled.

TONY ABBOTT: No-one should escape justice just because he or she is a member of the Gillard Government and his or her vote is needed for the Gillard Government to survive.

TOM IGGULDEN: Today's announcement from the DPP is a significant free kick for the Prime Minister, as she launched a new soccer team in western Sydney this afternoon.

JULIA GILLARD, PRIME MINISTER: I don't have anything before me which would cause me to alter from my previous statements of confidence in Mr Thomson.

TOM IGGULDEN: The Fair Work report's so secret, not even Mr Thomson's seen it.

CRAIG THOMSON, LABOUR MP: We found out about this on Twitter.

TOM IGGULDEN: That again is consistent with advice from the Government solicitor, who told Fair Work, "Any disclosure to the DPP should be made on a limited and confidential basis".

And what the Prime Minister and the public doesn't know can't hurt her.

JULIA GILLARD: I don't have a copy of this Fair Work Australia report. Mr Abbott doesn't have a copy of this Fair Work Australia report.

TOM IGGULDEN: And she's turned the Opposition Leader's call for Fair Work to release the report into an attack, suggesting he's interfering with an independent body.

JULIA GILLARD: I mean, would you really want a circumstance where Mr Abbott, if he was ever elected Prime Minister, could issue an edict and tell the industrial umpire to strip penalty rates out of every award in the nation?

TOM IGGULDEN: The manoeuvres that have led us to this point haven't been edifying for Fair Work Australia, but there's little the Opposition can do short of moral persuasion to expose what the industrial umpire found out about the allegations against Craig Thomson, allegations he continues to deny.